Signaling system



Patented Get. 13, 1925.

UNITED STATES i PATENT QUINCY A. Banana-r1', oifsrninormnn, MAssAcHusE'rrs, AssiGNoa 'ro wEsrING-f HOUSE ELEc'rBIca MANUFACTURING COMPANY, a conrom'rron'or PENNSYL- VANIA.

SIGNALING SYSTEM.

. f -1 Applicaticnalcd September 2.1921. Serial No. 975350.V

" oscillator without directly connecting the microphone or key Within the supply circuit. 7

Another object ot my invention is to provide means for controlling the high-frea quency oscillations ot an arcV oscillatorA which will give complete control with great simplicity ot apparatus, and Which requires the handling of a small power bythe key or microphone. y

Hitherto, the control and` modulation ot high-'frequency oscillations from an osci1lat-.

` ingI are' have usually been accomplishedby controlling the radio-frequency circuit, as in the well known-compensated wave and other similar methods. This has not prove altogether satisfactory, since often radia#v *tions were given out Which, While not 01," the vsending frequency, often caused Wireless intlsiference. Telephony has the radio-:frequency circuit,.hut asfthe'microphone had to handle the entire power it has heen possible to telephone only at low.

power. I

'lhe Poulsen-typev arc will oscillate only if its supply current is substantially con.-

stant in value. This is usuallyT accoin plished hy connecting the ield-magnet coils used to extinguisl'i the arc in series With the supply circuit. These ield-magnet coils in ,Y practice are universally milch larger and "higher in enorgy-stomne;y power than is necessary tor the constant-current cflect.

'l so arrange the circuits that the fieldiiagri'ict coils will not contribute to the con- Lantcurrent eli'ect in the arc supply. The 'uirect-current source of supply for the arc will then have a constant-potential characbeen accomplished hy inserting" a microphone in teristic Witlia-minimum of constantcurrent characteristic. In the supply. leads tothe arc. I insert .an inductivedevice, which vvI calla sustaining' inductance, of approxi-A mately just sufficient size to give tlie'minimum constant-current ei'ect to enable the arc to generate high frequency oscillations.` Associated in'ductively uWith this sustaining inductance is a controlling inductance located in a control circuit and so arranged that in signaling the constant-current effect of the sustaining inductance may be partially or `entirely destroyed, thus stopping the arc oscillations-or at least reduclng the output.

I may employ a separately excited orV shunt excited control circuit as desired. If under Acertain conditions 'of operation, the

hack E. M. F. generated by the variation ofy current in the sustaining inductance is ohjectionalold',If'inay utilize an E-type core member so Wound that the flux lines prol 'duced by; the sustaining inductance `canoe each other and produce a zero effect in the ,controlling inductance. The controlling inductancegin this latter type operates to change 'thepermeahility of the core, which changes the value of the sustaining inductancc',f;j'whereby the highfrequencT output vottheare is varied. In other types, 1 may .liavetiie controlling inductance oppose the Isustaining'inductance to neutralize it and thereby reduce its eective value.

In thedrawing Figure 1 is a diagrammatic vvievv of a system embodying the principles of my invention.

Fig. 2 is a diagrammatic view of a` modiication of the system shown in Fig. 1.

In Fig. 1 l have shown a, supply circuiti comprising a direct-current generator 1 connected in series with a variable resistance 2, a sustaining' induction coil 3, and electrodes 4 and 5 of an arc. The sustairnii'igY induction coil 3 is of such inductance that` the constant-current -eect produced isy ap` proximately a minimum for the operation of the arc as a lgenerator of high-frequency current. This insures that there Will he sutlicicnt constant-current eii'cct in'the arc supply circuit to enable the arc to generate liiglrfrequency oscillations, but atthc same time, any diminution or change inthe value eci of the sustaining inductance of the coil 3 will aii'ect thel high-frequency output of the arc. f

AThe sustaining inductanee coil 3 is wound upon an iron core 6 having an air gap 6". Likewise, wound upon the core is a controlling induction coil 7, located inn shunt circuit which comprises the controlling 1nduction coil 7 and a. microphone 8. The controlling induction coil is wound to oppose the flux lines set up by the sustaining induction coil 3. The controlling induction coil 7 does not contribute to the constant current characteristic of the supply circuit and instead of having the circuit comprising the controlling induction coil i' and the microphone S, shunting the sustaining induction coil 3, l may, it desirethhave the micro-phone circuit separately excited.

For de-ionizing the arc gap, l have provided arc magnets 9 and l1 coniprising core members l2 and '13 wound with magneticing coils l-t and l5. respectively. A directcurrent generator 16, or any other suitable source ot 'direct current keeps a constant, strong field between the arc magnets 9 and 11, whereby the arc gap l. etween the electrodes l and 5 is quickly (lc-ionized. and the field may be. adjusted to the best value by means ofia variable resistor 1W.

An oscillating circuit in which the highi'requency output of the arc majv be utilized` comprises the arc electrodes `rt and a condenser 1T and an induction coil' Inductively coupled to the induction coil 18 in the oscillating circuit. is an induction coil 19 in an antenna. circuit comprising an antenna 9,1, and. i'ttlesirell. a raiiable condenser 2'2 through which the` circuit is connected to the ground.

ln operation. the generator l` supplies` currentto the are electrodes -t and 5 through the sustaining induction coil E3 justed, as before stated. to give a .utiicient constant-elurent effect to enable high-'trequeney oscillations to be set up in the oseillating circuit. The windings l-t and l5 ot the are magnets il and ll, respectively, are separately excited for the reasou that it is desired that they shall not contribute to thi` constant-current etlect. The amount ot current flowing in the, arc may be regulated by varying the variable resistance Q.

'Vhen speaking into the microphone tl, fiux lilies are setup in the. core 6 by .the controlling induction coil 7 in the microphone circuit. These tiux lines oppose those set up by the sustaining induction coi 3 Aandthe ettectivewalue of the sustaining induction coil 3 isreduced thereby. This affects the output oit' the oscillating are. Therefore, the radiations given out by the antenna are impressed with voice vibrations.v

In my system I have utilized an airgap in the core, for the sustaining induction which is adcoil and the controlling induction coil. rl'hesc coils maybe interleaved or `wound in anyv other desired fashion ,and the use of the airgap is not necessary to the operation et mydevice. However, I prefer to employ an air gap in the core because of the. quick dying down in the linx upon u lecrease in cur-. rent, which is peculiar to the Ly-pe of core.

It is to be understood that l". Amay connect the circuit `for exciting the irc magnets in shunt with thc supply circuit, it desired; the sole purpose in showing them separately excited being to clearly indicate that the windings ot the magnets Ydo not contribute to the constant-current effect of the sustaining inductance coil 3. t

I have shown a system for controlling the output of an oscillating arc whichdoes not require 4the use of control devices in the oscillating circuit, but which permits the speech modulation of the high-frequency output. In place of utilizing a microphone circuit, l may employ a key to etlec-tcontrol of current flow through the controlling induction coil.

In the modification shown in Figure 2, I have employed an E-type 'of core 23 having exterior legs 2l and an interior leg As in the previous moditication, I have shown vthis core as of the air-gap type to insure quick dying down of the vlinx upon release of the energy. Upon thc exterior legs Q-t ot the. E-type core 23 are wound sustaining induction coils 26, which are connected in such manner that the fluxes set up by them will oppose and neutralize one another in the central leg of the core. rUpon the central leg .25 is wound the controlling induction coil 27. induction coil I( is comprised in a sepa-- rately excited microphone circuit having a -suitable source of direct current 2S, which l have indicated as a battery, and a microphone transmitter Q9.

The controlling inductunc'e coil 27 operates to vary thc permeability of the core 2?. llpon speaking into the. microphone 9,0, lations are set up in the controlling induction coil 2T, which, by reason of the flux' lines set -up thereby, vary the permeability of the core 23.

The core 23 may be adjusted to operate near the knee et the saturation curve or near the low end of the curve, whereby large variations in the reuctanceot the sustaining induction coils 2G wound on the cone 23 may be obtained.V The induction coils 26, as in the case of the. previously described modication, are adjusted close to the mininiunr value that will vgive the necessary constantcurrent characteritstic for high-frequency oscillation of the aref Therefore. a change in their effective reactance will cause variations in the arc output. Upon speaking into the microphone 29, oscillations are set up in The controlling .ai the controlling induction. coil 27; The output of' the arc is .varied in accordance with the voiceyibrations, since the permeability of the core 23 -is lvaried in accordance with the voicevihrationst* Iii this .moiiificatom Il have' shown an apparatnsffr -cmitrolling the reactance of the sustaining-inductances in thesupply circuit of the oscillating 'arc by varying the permeabilityof the core upon which the sustaining inductance coils are Wound.

Since- I have not ,shown all the possible modifications of ni invention that may occur to those skille in the art, I desire that my invention shall be limited solely by the art.'

I claim as my invention: l. A method of `controlling the highfrequency output of an .oscillating are which appended claims and the scope of the prior' consists in changing the' permeability'of an iron core associated with an inductor in the supply circuit. Y

2. A method of controlling the highfrequency out ut of an oscillating arc which consists in su stantially saturating an iron core associated with an inductor in the supply circuit.

3. A method of controlling the highfrequency output of an oscillating arc having an inductor of the cored type in its supply circuit which consists in opposing the flux lines set up in the core of the inductor. p

et. A method of controlling the highrequcncy output of an oscillating arc having an inductor in its supply circuit which consists in opposing thev flux lines set up by the inductor.

5. A system for controlling the highrcquency oscillations of an oscillating arc comprising a supply circuit, a sustaining inductor in the supply circuit, an oscillating arc, an oscillating circuit and a controlling inductor t-he flux lines of which oppose those of the sustaining inductor, whereby the high frequency output of the arc may be controlled.

6. A system for controlling the highfrcquency oscillations of an oscillatin arc comprising a supply circuit, a sustaining inductor -iii the supply circuit, an oscillating arc, an oscillating circuit, a. controlling inductor the .flux lines-of which oppose those of the first mentioned inductor and a inicroplionesconnected to vary-:the current flow through the controlling inductor.

7. A systemy for controlling the lhighfreqeuency oscillations of an oscillating arc comprising a supply circuit, a sustaining inductor in said supply circuit, an oscillating arc, an oscillating circuit a controlling inductor iii shunt with said sustaining inductor, the flux lines of said controlling inductor opposing those of said sustaining inductor, whereby the-high-'frekluenoy output ofthe arc may be controlled. ,O

8. A system Jfor controlling the highfi'equency oscillations ot an oscillating 'arc comprising a supply circuit, a sustaining inductor in the supply circuit, an oscillating arc, an oscillating circuit, a controllingA vinductor in shunt with the sustaining inductor, the flux lines of ythe controlling induc:y tor opposing those of the sustaining' inductor, and a microphone connected to` vary the current flow through the-controlling inductor. 4 i Y 9. A system for controlling the highrequency oscillations of an oscillating arc comprising a supply circuit, a Vsustaining.: inductor inthe supply circuit, an. oscillating arc, an oscillating circuit, a controlling,r in- 1 ductor in shunt with the sustaining induc-y tor, the flux lines of the controlling inductor opposing those of the sustaining induc- A tor, and an air-gap core upon which said inductors are wound.

l0. A system for controlling the highfrequency oscillations of an oscillatingr arc comprising av supply circuit, a sustaining inductor in the supply circuit, an oscillating arc, an oscillating circuit, a. control inductor in shunt with the sustaining inductor,

the iux lines of the control inductoro'pposing those of the sustaining inductor, an airgap corc upon which said indue-.tors are Wound and a microphone connected to vary the current flow through thc controlling inductor. f ll, A system Afor -cont-rolling thc! highfrequency oscillations of an oscillating `arc comprising a suppl circuit, a sustaining inductor in the supp y circuit, an oscillating arc, an oscillating circuit, a separately excited magnetic lield for said arc and a controlling inductor the flux .lines ot' which oppose those of thc sustaining iiuluctor, whereby the high frequency output ol the arc may be controlled. i

12. A system for controlling the highfrequency oscillations ot an oscillating arc comprising a supply circuit, a sustaining inductor in the supply circuit, an oscillatthe current ow through they controlling inductance.

j M13. A-systein foreontrolling the high-freqngjefgy oscillations of an oscillating arc comprising"h supply circuit, a variable resistor in said supply circuit, a sustaining inductor in said supply circuit, an oscillating arc, an oscillating circuit, said sustaining inductor having approximately the ling inductor.

14. `A systeni for controlling' the high frequency oscillations of an oscillating are comprising a supply circuit, a sustaining inductor in the supply circuit, un oscillating src, an oscillating circuit, a core upon which the sustaining inductor is wound und a. controlling.,r inductor on said core. for changing the permeability of the core, whereby the high-frequcncy output of the arc may be controlled.

l5. A system :tor controlling the high- 'frequency oscillations of an oscillating arc Vcoinprising a supply circuit, :t sustaining,`

inductor in the supply circuit, an oscillating arc, an oscillating circuit, an iron core upon Wliichthe sustaining intluctor is wound, a controlling inductor on said core `tor chunging the permeability oli the core and a microphone connected to vary the current flow through the controlling intluct'or.

16. A system for controlling the highfrequenc'y oscillations of an oscillating arc comprising'a supply circuit, a sustaining' incluctor in the supply circuit, an oscillating are, an oscillating circuit, an. iron core upon which the sustainingl induct-or is Wound, and a separately excited controlling inductor on said core 'tor varying the permecbility of thel core` whereby the high-` frequency output of the arc may be controlled.

17. A system for controlling,r the highfrequency oscillations ot an oscillating,T are comprising a supply circuit, a. sustaining incluctor in the supply circuit, an oscillating are, an oscillating circuit, an iron core upon which the sustaining' inductor is Wound, a

'separately excited controlling' inductor on comprising a supplyfcircuit, a si'istaining inductor in the supply circuit, an oscillating are, an oscillating circuit, an i-t'y'fpe core upon which the Sustaining, incluctor is wound, and a controlling iutluctor ou saidv core for changing the pern'ieability ot the core whereby the high-ireiprcncy output of the arc niay be controlled.

19. A system for controlling the highrequency oscillations or' en oscillating" arc comprising a` supply circuit, a sustaining inductor in the supply circuit. an oscillating arc, a separately excited magnetic 'Field for said arc, an oscillating circuit, an iron core upon which the sustainingr intluctor is Wound and a controlling influctor on said core for changing the 'permeability ci the core whereby the high-frequency output of the arc may be controlled.

20. A systeni for controlling the highfrequency oscillations of .an oscillating arc comprising a supply circuit, a Variable resistance in the supply circuit, an oscillating' arc, an oscillating circuit, a sustaining inductor included in the supply circuit and having approximately the minimum Value possible 'for high frequency oscillations in the. oscilletinf` circuit, an iron core upon which the sustaining incluctor is Wound and a controlling incluctor cn said core 'for changing the permeability o the core, whereby the high-frequency output of the are may be controlled.

In testimony whereof, hav, hereunto subscribed iny nanie this twenty-sixth (luy of August, 192i.

'cerner A. snneicifrfr.

Cir 

